Communication problem with database server

hi i had multiple installation server with three server: master - database - mail
i changed two master and database server ip address now i have Communication problem with database server
also i changed ip addresses wherever but when i create user or database nothing happen in database server and there is nothing in log:

The slave server connects to the database of the master server with its ispcsrv* user, the user is defined in the two config.inc.php files of ispconfig. The creation of databases is then done on the slave by using the local mysql root login as defined in /usr/local/ispconfig/server/lib/mysql_clientdb.conf

i have these users in master database
but in /usr/local/ispconfig/server/lib/mysql_clientdb.conf i have username and root password of each server database
and correct password how to trace what happening it doesn't create database ?
there is any log?

The slave server connects to the database of the master server with its ispcsrv* user, the user is defined in the two config.inc.php files of ispconfig. The creation of databases is then done on the slave by using the local mysql root login as defined in /usr/local/ispconfig/server/lib/mysql_clientdb.conf

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also i don't understand ispcsrv* is on master database but database generated on slave database so this username is for slave database to connect to master database (so we make this user on master database ) how is it possible ?

i update this file: /usr/local/ispconfig/interface/lib/config.inc.php and set new master ip also i try to connect to master ip and ispcsrv2 user with password stored in /usr/local/ispconfig/interface/lib/config.inc.php and it could connect:
but when i run /usr/local/ispconfig/server/server.sh on slave db server i get:

Check the /etc/hsts file on the slave. And the database host is never an IP, so ensure that you dont enter an IP address in the config.inc.php files, the name of the master is always the hostname of the master.

Check the /etc/hsts file on the slave. And the database host is never an IP, so ensure that you dont enter an IP address in the config.inc.php files, the name of the master is always the hostname of the master.

if you mean by config.inc is /usr/local/ispconfig/interface/lib/config.inc.php its:View attachment 3734
it was ip (without i touched) then i changed to 192.168.1.5 and now put host as you said but i get same error

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Solved but it was ip in both config file and when i changed to new ip it works. now you say it's better hostname?

Solved but it was ip in both config file and when i changed to new ip it works. now you say it's better hostname?

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The files should contain the hostname as requested by the ispconfig installer. If they contain the IP, then you must have either changed that manually before or entered a wrong value during installation.